Jet engines may be divided into two classes: deflagrative and detonative combustion engines. Deflagrative engines are well known and are typically used in commercial jet airliners, for instance. In a deflagrative engine, the combustion process produces combustion product gases that are propagated at velocities in the range of a few feet per second. These gases provide motive force for a vehicle to which the engine is mounted.
In contrast, in a pulse detonation engine, motive force is provided by combustion products that result from a detonation process. These combustion products are propagated at velocities very much higher than the combustion products of deflagrative processes. Indeed, typical velocities are of the order of several thousands of feet per second. U.S. Pat. No. 5,345,758 of T. R. Bussing (hereby fully incorporated by reference to the extent consistent with the invention disclosed and claimed below) describes a pulse detonation engine and the principles applied in its operation. However, the patent does not show details of a liquid fueled pulse detonation engine.